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    <title>Document</title>
    <script>
        var x = 5
        var y = 6

        // and
        if(x>=5 && y>5){  
            console.log('条件整体成立')
        }else{
            console.log('至少一个条件不成立')
        }

        // or
        if(x> 5 || y>5){
            console.log('至少有一个条件成立')
        }else{
            console.log('两个条件都不成立')
        }

        // not
        if(!(x == y)){
            console.log('true')
        }else{
            console.log('false')
        }
    </script>
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